Database Concepts and Information Processing

Database Concepts

• Databases are a shared, integrated computer structure storing end-user data and metadata.
• End-user data are raw facts of interest to users.
• Metadata describes data characteristics and relationships.

Data vs. Information

• Data are raw facts.
• Information is processed data revealing meaning.
• Good information is accurate, relevant, and timely, crucial for good decision-making.
• Data are building blocks of information.

Transforming Raw Data to Information

• Common steps include data entry, storing raw data in a table, and presenting information in tabular or graphical formats.

Why Databases?

• Good decisions arise from good, data-derived information.
• Data management is efficient within a database.

Database Management Systems (DBMS)

• DBMSs are collections of programs that manage data structure and access.
• DBMSs enhance data management effectiveness and efficiency.
• A database functions like a highly organized filing cabinet, supported by powerful software (the DBMS).

Roles of DBMSs

• DBMSs act as intermediaries between users and databases/applications.
• DBMSs allow for data sharing among multiple users or applications.
• DBMSs combine different user perspectives into a unified data repository.

Advantages of DBMSs

• Enhanced data sharing and security.
• Improved data integration and consistency.
• Improved data access for ad-hoc queries.
• Improved decision-making through quality information (accuracy, validity, and timeliness).
• Increased user productivity.

Types of Databases

• Classified based on user count, location, data, and usage.
• Number of Users: Single-user (desktop databases) and Multi-user (workgroup and enterprise).
• Location: Centralized (single site) and Decentralized(distributed across multiple sites)/Distributed.
• Data Stored: General-purpose databases (e.g., LexisNexis, ProQuest) and Discipline-specific (e.g., financial, GIS, medical).
• Usage: Operational, analytical/warehouse (historically used for tactical or strategic decisions)

Disadvantages of Databases

• Increased Costs (hardware, software, training, maintenance).
• Management Complexity (resource, data safety, data security management).
• Maintaining Currency (frequent updates, patches).
• Vendor Dependence.
• Upgrade/Replacement Cycles (new functions, hardware).

The Historical Roots of Databases

• Databases evolved from manual to computerized file systems.
• DP specialists initially handled tasks like tracking and report generation.

A File System Critique

• Problems in file systems:
  • Lengthy development times for data retrieval.
  • Difficult to get quick answers (extensive programming).
  • Complex system administration with growing file counts.
  • Insufficient security and limited data sharing.
  • Extensive programming for change management.
• Structural Dependence: Access to a file depends on its structure. Changes require modifications to all programs accessing the file.

Data Redundancy

• Data redundancy is storing the same data multiple times.
• Islands of Information result from data scattering across multiple locations.
• Redundancy increases the chance of different versions of the same data and errors in updates.
• Data inconsistency, update, insert and deletion anomalies all result from uncontrolled redundancy.

Data Integrity

• The aim of database systems is to ensure data integrity (accuracy and verifiability).
• Integrity ensures that data mirrors the real world.
• Data integrity is the condition where data reflects real-world conditions & events.
• Data should be accurate, reliable, and consistent.

Database Systems

• Logical data stored in a single logical repository.
• Data is physically distributed among multiple storage facilities.
• DBMS eliminates most file system problems:
• Data structures, relationships, & access are handled by the system.

The Database System Environment

• Database environments comprised of components.
• Components include hardware, software, data, procedures, and people.

DBMS Functions

• Key functions of a DBMS include:
  • Data dictionary management.
  • Data storage management (performance tuning).
  • Data transformation/presentation.
  • Security management.
  • Multiuser access control.
  • Backup & recovery management.
  • Data integrity management.
  • Database access languages and application programming interfaces. Database communication interfaces.

Database Professional Careers

• Opportunities and required skills for database professionals.
• Career paths may involve development, design, administration, analysis, architecture, consulting, or security.

Summary of Key Topics

Database professionals design, develop, and manage databases. Key aspects include data and information distinction, data transformations and presentation of information, data storage structures, file systems vs. database systems, database management systems (DBMS) functions, DBMS advantages and disadvantages and the database system environment.